Pokémon Go Metal Coat How To Evolve Scyther Into Scizor, Onix Into Steelix, And How To Get The Metal Coat banner300x250
Much the same as with Scyther, Onix's original method of evolution in the traditional Pokmon games was a little awkward, again requiring both a trading partner and a Metal Coat to perform.
Not only that - Steelix shares the same method as the Scizor evolution does in Pokmon Go, too. Simply earn yourself the right amount of Candy, pick up a Metal Coat, and evolve your Onix from the in-game menus.
As with Scyther and Scizor, again remember that this consumes the Metal Coat item when used to evolve your Onix into Steelix, so choose wisely before you confirm it!
Onix to Steelix Evolution cost - 1 Metal Coat and 50 Onix Candy
Want more help with Pokmon Go's Gen 2 update? Our list of new Gen 2 Johto Pokmon can teach you where to find each one, what you need to know about new Pokmon Go Berries, Special Items to evolve Pokmon such as King's Rock, Sun Stone, Up-Grade, Dragon Scale and Metal Coat, and how to get Eevee evolutions Umbreon, Espeon, and updated Egg distances and best Pokmon charts, as well as other Pokmon Go tips, tricks, cheats and guides.
Source : http://www.eurogamer.net/articles/2017-02-22-pokemon-go-metal-coat-how-to-evolve-scyther-into-scizor-onix-into-steelix-and-how-to-get-the-metal-coat-4819